Coumarins from the stems and leaves of Clausena dunniana H. Lev

Phytochemical study on the stems and leaves of Clausena dunniana H. Lev. led to the isolation and identification of 14 coumarins (1-14). Their chemical structures were determined on the basis of MS, NMR, and further supported by comparison with those reported in the literature. This is the first report that compounds 1-2, 4, 8, and 12-14 are present in the genus Clausena, and all of these compounds were isolated from C. dunniana for the first time. The chemotaxonomic significance of these isolated compounds was discussed.